Wire rope center



De@ 26,' '1939. F. R. METCALF 2,184,502

WIRE ROPE CENTER Filed Ilay 6. 1938 o isjcomposed of a plurality of strands il.

Patented Dec. 26, 1939 UNITED STATES PATENT OFFICE t. ROPE CENTER Application May s, 193s, serial No. Y206,450

s claims. (ci. 57153) 'I'his invention relates to improvements in wire ropes and, particularly, to wire rope centers.

Primarily, the object of the invention is-to provide a wire rope center better adapted to support the strands of the wire rope, in that the crevices between the wires of the strand will be .more completely Afilled by the center. Y Another object is to provide a wire rope cenl ter having a substantially smooth surfacefree of irregularities or undulations. In present-.day practice, multi-strand rope of comparatively small cross-section is commonly u'sed for wire rope centers and the spirally extending indentations formed in the surface ofthe rope by the spiral disposition of the several strands interfereswith or prevents proper positioning or supporting of thestrands on the center, by reason of-the fact that the center does not properly fill the crevices between the wires of the individual strands of the wire rope.` With the present invention, these diiiculties are eliminated by reason of the fact that the surface of the present center is free of the spirally extendingV indenta- .tions or other irregularities. i

.A still further object of the invention is to provide a wire rope center in whichthe lubricant for.' the i'lbres of the strands of the center will be retained therein, this preferably being accomplished by the use of a material for filling the indentations in the surface of the center that is capable of functioning as a seal for retaining the lubricant in the center strands.

, With these and other objects in view, the invention consists in certain details of construction 85 and combinations and arrangements of parts, all

as will hereinafter be more fully described and.

-The present inventionjs shown in connection` with the usual wire rope construction, the same comprising a plurality of wire strands Ill laid spirally 'on the' center or core C. The preferred form of center illustrated inthe present instance :strands 'which may be of vegetable bres are, of course, formed'gof a multiplicity of spun yarns and the -several1 =strands are twisted together in The' ` accordance with ordinary practice, so that there is formed on the surface of the center a plurality of'spirally disposed indentations i2, sometimes referred to as contlines. In present-day wire strandl rope manufacture, where ropes of small cross-section are used and have these spiral indentations in the surface thereof, the presence of these indentations interferes with the proper seating or positioning of the wire strands on they core or center, due to the fact that the irregularitiesin the cross-section of the center prevent the crevices in the individual wirestrands being uniformly and completely filled by the fibrous body formedvby the center.

In accordance with thepresent invention, these diiiiculties are eliminated by filling the indentations with a plastic,material, preferably a cellulose base material or, if desired, synthetic plastic materials or solutions of the same may be used for this purpose. For reasons which will later appear, it is preferred to at least slightly coat the entire surface of the stranded fibre core. The body of material constituting this filler lfor the irregularities in the surface of the fibre core and the coating of the center is indicated at I3 and, as is more clearly seen in Fig. 3, the result f is the production of a center of substantially circular cross-section so that, when the wire strands of. the rope are laid on the center, the crevices in the surface of the individual strands of the rope at the points where they contact the surface of the center will'be uniformly lled. It is, of course, understood that the wire strands of the-rope carry the-tensile stresses, but upon being wound on the center, impose compressive strains on the center, to the extent that the wire vstrands are embedded in the center to at least partially ll the valleys or spiral depressions formed by thesurfaces" of contiguous wire strands. However, with a center such as the present, having a truly cylindrical surface formed of material moldable in the sense that it can ow, so to speak, into the crevices in the surfaces ofthe wire strands when placed under compression by those strands', the several strands will naturally be uniformly supported at all points on the surface of the center.

It is also important that the strands of wire rope centers, or rather the fibres of which the center is formed, be properly and adequately lubricated and. as a rule, the desired quantity of e lubricant is incorporated in the same during Athe production thereof. This is true, whether the center is of strand formation or formed of a single `body of vegetable fibres, asydistinguished from a multi-strand construction. With this thought in mind, the filler material i3 should also be capable of functioning as a seal for retaining the lubricant in the core or center. The material i3, therefore, serves a dual function, in that it insures uniform support for the wire strands of the :ope or cable and, in addition, efficiently seals the fiber center to prevent loss of lubricant.

As just indicated, it will be appreciated that the center need not be of multi-strand construction, but might well be a large, single body of bres which may be termed, for the purposes of the present invention, a single strand, although, in the rope industry, it would probably be more properly referred to as a sliver of fibres made up into a-center. It will also be appreciated that the present invention is not necessarily limited to use in connection with centers or cores made of spun fibres, as the use of paper in the production of centers is also possible, as indicated in Patent No. 1,916,135. `It is also to be understood that the invention is not limited to a filler material capable of functioning as a seal for the lubricant in the center, as it is entirely possible that this feature might be omitted in the sense that the filler material will function solely to eliminate irregularities in the surface and cross-section of the finished center.

One mode of carrying out the present invention comprises passing the core or center, whether it be of single or multi-strand construction, through a bath of fluid or plastic material of cellulosic base that will penetrate, to some extent, the outside surfaces of the fibres constituting the center, after which the center is passed through a` bath of cellulose base materials, or a compound of such materials, whereby a coating is applied to the core. The interstices or valleys formed by the strands of the core, or other irregularities in the surface thereof, will be filled with this filler material, which blends With the core by means of cohesion between the cellulose materials and the exterior of the rope structure. After passing through such a bath, the coated core is passed through a. die to wipe oi surplus cellulose materials and thence through proper drying and conditioning equipment. These steps may be repeated, depending upon the amount of coating material applied by each immersion of the core in the bath, the principal point being that sufcient coating material is applied Ato produce a core of circular cross-section and, preferably, to entirely coat the surface so as to seal the lubricant in the core.

As to the ller materials used, cellulose ethers and esters, such as ethyl cellulose, cellulose nitrate and cellulose acetate are, at present, believed to be preferred.

What I claim is:

1. A center for wire ropes comprising a plurality of lgroups of bres twisted together forming a body having depressions extending spirally of its surface,` a lubricant incorporated in said body, and sealing material substantially covering said body and capable of retaining the lubricant therein, said sealing materialalso filling' said depressions to impart an even surface substantially free of undulations to the center.

2. A center for Wire ropes comprising a plurality of groups of fibres twisted together forming a body having depressions 'extending spirally of the body, a cellulose base material filling said depressions, and a lubricant incorporated in said fibre body, said filler material sealing said lubricant in said body and imparting to said body an even surface free of undulations.

3. A center for wire ropes comprising a plurality of fibres associated to form an elongated body, said body having depressions or irregularities in its exterior surface, and a cellulose base 

